United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                     ___________

                                     No. 00-1528
                                     ___________

United States of America,                 *
                                          *
             Appellee,                    *
                                          *
      v.                                  * Appeal from the United States
                                          * District Court for the
Christine M. Heliin,                      * District of Nebraska.
                                          *
             Appellant.                   *     [UNPUBLISHED]
                                     ___________

                            Submitted: November 7, 2000
                                Filed: November 16, 2000
                                    ___________

Before RICHARD S. ARNOLD, HANSEN, and BYE, Circuit Judges.
                           ___________

PER CURIAM.

       Christine Heliin pleaded guilty to conspiring to distribute and possess with intent
to distribute methamphetamine, in violation of 21 U.S.C. § 846. After an evidentiary
hearing on the issue of drug quantity, the district court1 sentenced her to eighty-seven
months imprisonment (the Guidelines minimum) and four years supervised release. On
appeal, Heliin argues that she was coerced into pleading guilty, that the court’s drug-




      1
       The Honorable Richard G. Kopf, Chief Judge, United States District Court for
the District of Nebraska.
quantity determination was not supported by sufficient evidence, and that the court
erred by not departing sua sponte on the basis of her post-offense rehabilitation.

       We reject each of these arguments. Heliin’s failure to attempt to withdraw her
guilty plea below precludes her from challenging its voluntariness in this appeal. See
United States v. Murphy, 

, 716 (8th Cir. 1990) (claim of involuntary guilty
plea “first must be presented to the district court and [is] not cognizable on direct
appeal”). The district court’s drug-quantity finding was based on credibility
determinations, which we see no reason to disturb on appeal. See Anderson v. City of
Bessemer City, 

, 575 (1985) (findings based on credibility determinations
are virtually never clear error); United States v. Sample, 

, 1034 (8th Cir.
2000) (credibility determinations are committed squarely to domain of sentencing court
and are virtually unreviewable on appeal). Finally, the court did not plainly err by not
sua sponte granting a downward departure. See United States v. Montanye, 

, 192 (8th Cir. 1993) (en banc) (plain-error standard of review for issues not raised
below).

      Accordingly, we affirm the judgment of the district court.

      A true copy.

             Attest:

                     CLERK, U.S. COURT OF APPEALS, EIGHTH CIRCUIT.




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